Roots,iterations and logarithms of formal automorphisms

In this paper it is proved that having a logarithm is equivalent to having roots of arbitrary order in the group of automorphisms of a formal power series ring, and in algebraic subgroups too     

The truncatedSVD as a method for regularization

The truncated singular value decomposition (SVD) is considered as a method for regularization of ill-posed linear least squares problems. In particular, the truncated SVD solution is compared with the usual regularized solution. Necessary conditions are defined in which the two methods will yield similar results. This investigation suggests the truncated SVD as a favorable alternative to standard-form regularization in cases of ill-conditioned matrices with well-determined numerical rank.This work was carried out while the author visited the Dept. of Computer Science, Stanford University, California, U.S.A., and was supported in part by National Science Foundation Grant Number DCR 8412314, by a Fulbright Supplementary Grant, and by the Danish Space Board.     

MLE20/MJD20在甲类功率放大器中的应用

针对传统甲类功率放大器电路复杂、电路稳定性较差的缺点,设计开发了一种新的基于全对称互补差分放大电路的甲类功率放大器。该放大器采用MLE20/MJD20绝缘栅型场效应管作为电流放大管,通过对差分输入级、电压放大级、功率输出级中各元件参数的合理设计,降低了功率放大器的输出内阻,提高了电路的驱动能力及电路的稳定性。     

温室大棚多点温度采集系统的设计与实现

针对目前在温度采集电路中的不足,结合一般温室大棚的功能需求,提出了一种基于FPGA的多点温度采集系统,本系统采用HX—EP2C8-V5型FPGA开发板作为研发平台,以DS18820作为温度传感器,利用FIR滤波器实现对采集信号的去噪处理,实现对温室大棚内多点温度采集,当测量温度超过设定范围时,可实现自动报警。文章详细分析了系统功能需求,结合QuartusⅡ给出了温度定期及按键选择采集模块、DS18820温度采集模块以及FIR滤波器的仿真结果。     

基于MSP430单片机的超低功耗温度采集系统设计

针对工业生产过程中常需对温度进行实时监控的需求,本文介绍了一种便携式超低功耗的温度采集与实时显示的温度采集系统。为了使温度采集系统功耗达到最低,本设计选用了TI公司的超低功耗MSP430FG4618单片机作为主控芯片,并对整个系统进行了有效的电源管理,最后采用FYD12864C-1液晶显示器将采集到的温度实时显示出来。...     

基于单片机的高精度温度测量系统设计

提出采用单总线数字式温度传感器DS18B20和单片机组成的新型高精度温度测量仪的设计。介绍了温度传感器DS18B20的结构、特点和工作原理,设计了DS18B20和AT89S52单片机的温度测量系统硬件电路和软件编程,主要包括温度采集、温度显示及报警控制等功能。整个系统具有结构简单,测量精度高,传输距离远,抗干扰能力强,温度读取方便和造价低等一系列优点,适用于生产生活及科学研究中对温度的测量,应用前景十分广阔。